Employees at Spalding Bakery have been warned that 46 jobs could be cut.
A spokesman said a consultation process has begun at the Fulney Lane site.
They added: “We are proposing to restructure the current shift system in order to streamline our processes and identify essential efficiencies.
“Regrettably, there is still the potential that 46 jobs could be lost. We fully recognise how hard this proposal is on affected employees and, should it be progressed, we will work closely with our employees and their representatives to look for every opportunity to minimise potential job losses.”